UK SMS Sender ID Registry: Rules for Business Senders

As of 2026 the UK has no mandatory sender ID registration and no mandatory central SMS sender ID registry: alphanumeric sender IDs, UK long numbers and short codes all work. But protected brand names are blocked unless the brand has authorized your route, generic IDs such as INFO or SMS are filtered, and Ofcom now requires operators and aggregators to check every business sender. Marketing texts need consent under PECR.

Rules last checked: October 2026.

Sender ID registration

There is no national register you must file with before sending. Instead, control sits with two layers:

• The MEF SMS SenderID Protection Registry. Run by the Mobile Ecosystem Forum, it lets brands (mostly banks, government departments and other high-risk names) register their sender IDs and the routes allowed to use them. Participating aggregators and operators block messages that use a protected ID from an unauthorized source, and a separate list targets lookalike spellings. Brands join it; senders who are not the brand cannot register its name.
• Ofcom's anti-scam rules. In a statement published on 15 July 2026, Ofcom decided not to create a mandatory central sender ID registry for now. Instead it is adding conditions that require mobile operators and aggregators to carry out KYC on business senders, check that each requested alphanumeric sender ID matches the business and its stated purpose, keep policies on protected and generic IDs and special characters, and block scam traffic in transit. Where a provider does not onboard the sender directly, it must pass these checks down by contract.

In practice, expect your route provider to ask who you are, which sender IDs you will use and why, before traffic is opened. Using a well-known brand name you do not own will fail. See how sender ID registration works.

Sender ID types and blocking

Stick to letters, digits and simple separators in alphanumeric IDs: operators restrict special characters, and providers recommend nothing beyond period, hyphen, underscore, space and ampersand. BT and EE block brand-related sender IDs by default until they are allowlisted. More on formats in SMS sender ID types.

Consent and opt-out under PECR

Marketing texts fall under PECR (the Privacy and Electronic Communications Regulations), enforced by the ICO. The rules:

• Marketing needs prior consent given by a positive action; pre-ticked boxes or silence do not count.
• The "soft opt-in" exception covers existing customers who gave their number during a sale, for your own similar products, provided they could refuse at collection.
• Every marketing message must give a simple way to opt out.
• Pure service messages (order updates, appointment reminders, OTP) are not marketing, but adding promotional content makes them marketing.

The ICO regularly fines companies for unlawful marketing texts, and consumers report spam by forwarding it to 7726, which operators use to block senders. See transactional vs promotional SMS.

Restricted content

Age-restricted content such as alcohol and gambling is allowed, but UK carriers review it case by case. Cannabis content is prohibited, while CBD is permitted. Shortened URLs from public shorteners are blocked by some providers, so link to your own domain. For short codes, express consent is required before the first message, and friend-to-friend invites or lead-generation opt-ins are not accepted. More in SMS content restrictions.

Mobile networks and OTP traffic

The UK has three network groups: EE (part of BT), VodafoneThree (formed by the merger of Vodafone UK and Three UK) and Virgin Media O2. Many MVNOs, such as Sky Mobile, Lebara and Lycamobile, ride on them. Messages are 160 GSM-7 characters or 70 in Unicode; accented letters such as umlauts may be replaced, so test templates.

For OTP, use a consistent alphanumeric ID tied to your brand rather than a generic one, keep the message plain with no links, and monitor delivery per network. Watch for traffic spikes to unusual number ranges, a sign of SMS pumping, and avoid cheap routes that bypass these checks: grey SMS routes are a common cause of sudden blocking. See also OTP SMS best practices.

Coverage details are on the United Kingdom SMS destination page and our A2P SMS service. VoIPMatcher sources the route from its carriers and manages it; buyers and sellers never see each other. Request a UK SMS route.

Frequently asked questions